Field of the Invention
The present invention relates to a method for making a composite material wheel rim and, in particular, to a method of making the wheel rim providing drilled threaded holes after it is fully formed according to the spoke amount of the requested wheel hub and the assembled angle of each spoke to fit different types of wheel hub units to increase the yield rate and reduce the inventory of the wheel rims.
Description of the Prior Art
To equalize the spoke tension of a bicycle wheel unit, generally, the wheel unit is radially arranged with a plurality of spokes for connecting the wheel rim of the wheel unit and the wheel hub. Not all the assembled angles of the spokes are the same, so that the connecting position of each spoke at the inner surface of the wheel rim needs to be drilled with the threaded hole in compliance with the orientation angle of each spoke to fit and connect each spoke. A prior art method of making a wheel rim, such as the method disclosed in US 2007/0102995 (hereafter the prior art case), involves: (a) forming an annular metallic rim member (annular metallic rim member 22); (b) bonding a plurality of reinforcement members (reinforcement members 23) providing pre-formed threaded holes with different angles (threaded bore 23c) to the inner surface of the annular metallic rim member (annular metallic rim member 22) by adhesive, with the bonded positions of the reinforcement members and the angle of the individual threaded hole which each bonded position requires configured according to the requested spoke amount of the wheel hub and the orientation angles of the discrete spokes; (c) using the adhesive attachment materials or sheets (adhesive attachment materials or sheets 24) to overlie all of the plurality of reinforcement members to integrate the reinforcement members with the annular metallic rim member; and (d) using a drill to individually drill the opening of the pre-formed threaded hole (threaded bore 23c) in each reinforcement member covered by the adhesive attachment materials or sheets, such that the wheel rim disclosed in the prior art case is completed.
However, the prior art case described above has deficiencies in manufacturing as follows:
(I) The reinforcement members (reinforcement members 23) disclosed in the prior art case involve diverse reinforcement members with various angles of threaded holes, so that the diverse reinforcement members need to be separated from one another carefully. Otherwise, it is easy to mix and result in using incorrectly. Thus, the pressure of the storage administrator in inventory management may increase during stock preparation.
(II) Basically, different threaded holes provide different spoke assembled angles, so that each reinforcement member with a threaded hole should be placed at an accurate position fitting the orientation angle of the spoke mating with it when the wheel rim is completely formed. If one of them is arranged wrongly, the wheel rim may become a defective unit which can not be used. Alternately, if the reinforcement member is disposed correctly but is positioned in an inaccurate direction, that causes the threaded hole to provide an incorrect angle, so that the wheel rim also becomes a defective unit. Therefore, the prior art case has the drawback of high product defect rate.
(III) The wheel rim disclosed in the prior art case can only be applied to the type of wheel hub with which the wheel rim allows to mate. That is, other types of wheel hubs can not fit such a wheel rim, and, thus, different types of wheel rims need to be stocked separately, so that the inventory cost of the wheel rims is increased.